Block alignment for microtomes

ABSTRACT

Systems and methods described herein for aligning a block in a microtome attempt to save time, money, and the sample by aligning a block in any rotary or cryostat microtome. One such device for aligning a block in a microtome has a knife holder component removably attached to a knife holder of the microtome and a pin alignment component extending vertically from the knife holder component in a direction substantially parallel to the block. The pin alignment component has a plurality of front pins extending from a front surface of the pin alignment component configured to slide in response to an angle of the block and a plurality of rear pins extending from a rear surface of the pin alignment component and coupled to the front pins. The rear pins are configured to indicate the extension of the front pins from the pin alignment component.

This invention was made with Government support under contractN01-CO-12400 awarded by the National Cancer Institute. The Governmentmay have certain rights in the invention.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates generally to systems and methods for aligning orrealigning a block specimen in a microtome.

2. Background

Scientists and medical professionals often analyze tissue from humans,animals, or other biological specimens in a microscopic examination todiagnose various diseases and conditions. One method of preparing thesespecimens for histological examination is through the use of a rotary(also known as a table microtome) or cryostat microtome. Microtomes aremechanical devices used to consistently create thin sections, typicallybetween 5 and 10 μm, of biological specimens. When cutting on a rotarymicrotome, harvested specimens reside in blocks of paraffin, whereas incryostat microtomes, specimens are embedded in optimal cuttingtemperature (OCT) frozen media. In contrast to the rotary microtome, thecryostat microtome has a microtome unit mounted in a cooling enclosurewith externally mounted controls. After the specimens are sliced ineither type of microtome, the sliced sections can be stained andexamined.

Generally, in operation of a rotary or cryostat microtome, the blockhaving the specimen (referred to herein as a “block specimen”) issecured to a chuck and clamped into the microtome. By fixing the chuckto the microtome, a user can align the block specimen along any of threeplanes (i.e., in X-, Y-, and Z-planes) in juxtaposition to a stationarythin knife (or blade). Once the block specimen is aligned with theknife, the user conducts a process known as “facing” or “truing” theblock specimen.

During the truing process, the user operates a handwheel on themicrotome to advance the block forward and vertically across the surfaceof the knife until complete sections of the block specimen areconsistently sliced and the specimen itself is substantially exposed.Each rotation of the handwheel actuates mechanical gearing within themicrotome to incrementally advance the block specimen forward forcutting the next (serial) section. Once the user obtains a desiredsectioning surface and depth, the user can begin to slice sections foranalysis. However, the conventional truing process has its limitations.

Slight misalignments of the block specimen to the knife or imperfectionsin the flatness of the block specimen's surface in juxtaposition to theknife can result in an incomplete section unsuitable for subsequentanalysis. As slicing continues during the truing, incomplete sections orslices may contain specimen, as opposed to being entirely paraffin, andmay be discarded. Furthermore, because many conventional microtomesallow the chuck to be adjusted in all three planes, it can be verychallenging for sets of block specimens cut on a single microtome or forblock specimens cut on different microtomes to have cutting planes thatmatch in all three planes. For example, using a manual, time-consumingprocess, a user can attempt to align a block specimen by adjustingvarious angles of the chuck and then slicing a section with the knife toascertain whether the block specimen's surface is substantially alignedwith the cutting plane of the knife. This trial-and-error process isrepeated until the user can slice a full section of the block. Moreover,microtomes are not designed to record the alignment angles by which agiven block specimen resides within a chuck, so block specimensreturning to a microtome for further slicing may require the user toconduct the time-consuming alignment process. Microtomes are also notengineered to automatically re-align the chuck to match the cuttingplanes of previously sectioned blocks, thereby requiring manualrealignment by a user. As a result, the user may need to re-true theblock each time it is positioned for slicing in a microtome. Manualrealignment of the block can be very tedious and difficult. Andsequential re-truing of blocks typically results in a substantial lossof sample before a complete section is properly sliced. Even those userswho re-embed the entire block specimen or the specimen itself in a newblock and then attempt to align the newly formed block specimen wouldsimilarly encounter these challenges.

Conventional attempts to align a block within a microtome areinsufficient. For example, Microm's histo collimator attempts to align ablock using a laser. In its general operation, the histo collimator usesa sight, a light source, and a mirror. The mirror is mounted on thesurface of the block and reflects the light back to a crosshair in thesight. When a light beam from the light source is centered on thecrosshair, the block is aligned in the horizontal and perpendicularplanes. However, this equipment is very expensive and is operable ononly Microm's microtomes. In another example of conventional equipment,such as those made by Newcomer Supply, Advanced Innovations, and MarketLab, a microtome aligner can set the microtome to zero in the X-, Y-,and Z-planes. If a plane is not set to zero, the block will not beproperly aligned. For example, when using a block that was previouslycut on a different microtome, the block aligned along a zero X-, Y-, andZ-plane of one microtome may not correlate to a zero X-, Y-, and Z-planeof another microtome. Additionally, a zero plane for a chuck holding ablock does not necessarily correlate to a block surface perpendicular tothe knife, so the block may require further alignment. This equipment isalso expensive and is operable on only certain microtomes.

In addition to the disadvantages of the conventional equipment foraligning blocks in rotary microtomes, none of this conventionalequipment is applicable to cryostat microtomes. Indeed, after over 100years of advances in microtome technology, there still exists a need foraccurately and consistently aligning and realigning block specimens inmicrotomes, as well as an alignment system or method that can be used ondifferent types of microtomes.

SUMMARY OF THE INVENTION

Various embodiments described herein attempt to save time, money, and/orconserve the sample by aligning or realigning a block in any rotary orcryostat microtome, thereby eliminating or substantially reducing a needfor aligning previously cut blocks. Embodiments of the systems andmethods described herein can align tissue samples residing in a paraffinwax or OCT frozen media blocks in a substantially consistentthree-dimensional orientation within a histological microtome orcryostat microtome prior to histological sectioning. As one potentialbenefit, the embodiments described herein may allow a user to moreexpediently and more accurately align and realign blocks in a microtome.As another potential benefit, the embodiments described herein mayprolong the sharpness of a microtome knife, which needs to beperiodically replaced or sharpened. These embodiments may prevent wasteof specimens due to less truing. As a result, because less truing, andlikely less training, may be required, specimens may be sliced moreexpediently, which can assist in preserving biological integrity.

In one exemplary embodiment, a device for aligning a block specimen in amicrotome has a knife holder component removably attached to a knifeholder of the microtome and a pin alignment component extendingvertically from the knife holder component in a direction substantiallyparallel to the block specimen. The pin alignment component has aplurality of front pins extending from a front surface of the pinalignment component configured to slide in response to an angle of theblock specimen and a plurality of rear pins extending from a rearsurface of the pin alignment component and coupled to the front pins.The rear pins are configured to indicate the extension of the front pinsfrom the pin alignment component.

In another exemplary embodiment, a method for aligning a block specimenin a microtome has the steps of attaching a pin alignment component to amicrotome, wherein the pin alignment component comprises a plurality ofpins, moving the block specimen in the microtome into a position to abutat least one of the plurality of pins, and re-positioning the blockspecimen in the microtome so that substantially all of the plurality ofpins contact the block specimen at about the same distance from the pinalignment component.

In yet another exemplary embodiment, a microtome block specimenalignment component having a pin alignment component comprising aplurality of pins has a means for engaging the microtome block specimen,and a means for measuring the extent that the means for engaging hascontacted the microtome block specimen.

Additional features and advantages of an embodiment will be set forth inthe description which follows, and in part will be apparent from thedescription, or may be learned by practice of the invention. Theobjectives and other advantages of the invention will be realized andattained by the structure particularly pointed out in the exemplaryembodiments in the written description and claims hereof as well as theappended drawings.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory and areintended to provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The preferred embodiments of the present invention are illustrated byway of example and not limited to the following figures:

FIG. 1 shows a side view of a microtome with an alignment componentaccording to an exemplary embodiment;

FIG. 2 shows an alignment device according to an exemplary embodiment;

FIG. 3 shows a cross-sectional view of a pin alignment componentaccording to an exemplary embodiment;

FIGS. 4 a to 4 c show views of a pin alignment component according to anexemplary embodiment;

FIGS. 5 a to 5 b show views of a pin alignment component according toexemplary embodiments;

FIGS. 6 a and 6 b show a cross-sectional view of a lever operationaccording to an exemplary embodiment;

FIGS. 7 a to 7 d show methods of lever configuration according exemplaryembodiments;

FIG. 8 shows an alignment device having a brush according to anexemplary embodiment; and

FIG. 9 shows an alignment device having a digital display according toan exemplary embodiment.

DETAILED DESCRIPTION

Reference will now be made in detail to the preferred embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings.

The various embodiments and configurations are not intended to belimited to any particular type of microtome or microtome model. In fact,many embodiments described herein are intended, although not required,to be interchangeable with various microtomes. In one example, themicrotome can be a rotary microtome, such as the Leica MicrosystemsRM2255 rotary microtome, or a cryostat microtome, such as the LeicaMicrosystems CM3050S cryostat microtome. The embodiments can beconfigured for use in a rotary or cryostat microtome with minimalvariation, including the use of materials suitable for room temperatureor a cooler environment. In another example, the microtome can be aslide microtome or a disk/saw microtome, as well as an automatedmicrotome. Thus, although the exemplary embodiments illustrate a rotarymicrotome, it is not intended to be limited to that particularmicrotome.

Referring to FIG. 1, a side view of a conventional rotary microtome 100having an exemplary alignment device 190 is shown. In order to secure ablock specimen 130, microtome 100 has a block clamp 110 having a blockcartridge or chuck 120 that holds the block specimen, e.g., paraffin orOCT block, 130. A clamp adjustment knob 140 can be used to secure thechuck 120 and block specimen 130.

In order to slice the block specimen 130, a knife holder base 150 has aknife holder 160 and a knife blade 170. The angle of the knife holder160 and the knife blade 170 can be adjusted using a clearance angleadjustment 180. According to one embodiment, the alignment device 190 ispositioned on the knife holder 160, and can be attached using magnetism,a clamp, screws or bolts, or any other attachment mechanism known to oneof ordinary skill in the art. As described in further detail herein, thealignment device 190 can assist a user in aligning the block specimen130 at an optimal angle for slicing. The alignment device 190 accordingto this exemplary embodiment is shown in more detail in FIG. 2.

Referring to FIG. 2, an alignment device 290 is shown. Alignment devicecan be integrated into the microtome or may be an added component, whichcan be optionally removable from the microtome. Alignment device 290 hasa knife holder component 210 connected to a pin alignment component 220with a hinge 230. It is contemplated that the hinge can couple the knifeholder component 210 to the pin alignment component 220 in anyconfiguration such that the pin alignment component is rotatable aboutan axis extending through hinge 230 while the knife holder componentmaintains a stationary position on the knife holder. The knife holdercomponent 210 and the pin alignment component 220 can be a singlestructure or separate structures. In one embodiment, the knife holdercomponent 210 is disposable.

Based in part on the structural properties (e.g., hardness) of the blockspecimen 130 or a knife profile (e.g., an angle of the knife's edge),the clearance angle of the knife holder component 210 may need to beadjusted to prevent chatter or compression during slicing. As the knifeholder component 210 rotates, the pin alignment component 220 may nolonger reflect an upright orientation that is parallel to the knife'sslicing plane. Accordingly, in order to ensure that the pin alignmentcomponent 220 maintains a preferred orientation, the pin alignmentcomponent 220 can be adjusted to match the clearance angle of themicrotome. An angle indicator 240, which can identify the angle betweenthe knife holder component 210 and the pin alignment component 220, canbe used to match the angle between the knife holder component 210 andthe pin alignment component 220 to the clearance angle on the microtome,shown by the clearance angle adjustment 180 in FIG. 1.

Pin alignment component 220 has a plurality of front pins 250 extendingfrom a front side and a plurality of rear pins 260 extending from a rearside of the pin alignment component 220. Although front pins 250 andrear pins 260 are illustrated as cylindrical members, it is intendedthat front pins and rear pins can embody any shape to accomplish theirintended purposes. Pins 250 can be coupled to pins 260 so that movementof pins 250 is reflected by movement of pins 260. Pins 250 extendingfrom the front side of the pin alignment component 220 are intended tocontact a paraffin block. However, due to the size of the paraffin blockor the positioning and angle of the paraffin block, it is understoodthat not every pin 250 may contact the paraffin block.

Pins 260 extending from the rear of pin alignment component 220 can haveindicia such as lines, text (e.g., numbers), color, or other marking toindicate the extension of a pin from the pin alignment component 220. Ina configuration where the indicia are viewed by a human eye, the indiciahave sufficiently large distinctions to discern each indicia. In oneembodiment, the indicia are spaced approximately 0.75 mm to 2.0 mm inlength along the pins 260. For example, the indicia can be spacedapproximately 1.0 mm apart. In an alternative embodiment where amagnifying lens is used to view the pins, the indicia can be spacedapproximately 0.25 mm to 0.75 mm apart. For example, the indicia can bespaced approximately 0.5 mm apart. It is understood that the indicia inthese embodiments can be larger or smaller and are not intended to belimited to these exemplary embodiments. In an embodiment where colorsare used as the indicia, the colors are compliant with Section 508 ofthe Rehabilitation Act of 1973 and Rehabilitation Act Amendments of 1998so that color blind people can distinguish between indicia. In anexemplary embodiment, pins have alternating colors. In another exemplaryembodiment, each indicia is a different color. In yet another exemplaryembodiment, each indicia has a different pattern. Accordingly, theseindicia can allow a user to determine a preferred sample alignmentposition and repeat or change a sample alignment based on previouslypredetermined positions. Whether slicing a specimen for the first timeor realigning a block specimen that has been removed from a microtome,the indicia can provide a guide to the user as to how to adjust thespecimen to obtain a desired slice. Where one pin may be more extendedthan another pin (e.g., one pin may extend 1 mm and another pin mayextend 2 mm), a user can appropriately adjust the angle of the specimento the desired plane.

Pins 250 and pins 260 can be constructed of any durable material thatresists oxidation, such as stainless steel. It is desirable to use amaterial that can withstand a lot of movement, is highly durable, anddoes not bend. It may also be desirable to have a material that canwithstand high temperature and high pressure, such as those conditionsencountered in an autoclave. For use in a cryostat, it may be desirableto use a material that can withstand cold temperatures as well aschanges between a room temperature and cold temperature environment.

In an exemplary operation of alignment device 290, when aligning theblock specimen with the knife to minimize specimen loss, a user canadvance the block forward until it substantially abuts pins 250. Becausethe block will likely be in a plane differing from the desired slicingplane, pins 250 will extend at different lengths to contact the block.As a result, pins 260 will also extend at different lengths. Indicia onpins 260 provide the user with an indication of the plane of the blockspecimen and how that plane must be adjusted within the X-, Y-, andZ-planes. The user can calibrate the chuck holding the block so that thepins 260 reflect that the block is positioned in a desired plane.

In one example, the indicia on the pins 260 can be graduated bymeasurement of extension, such as by increments of 1 millimeter. Assuch, at a zero position where the block is not contacting the pins 250,pins 260 reflect a zero millimeter movement. Every millimeter (e.g., 1mm, 2 mm, 3 mm . . . n mm), there is a marker to indicate the extensionof the pin 260 from the pin alignment component 220. Before a blockspecimen is aligned, one pin may indicate an extension of 1 mm, whileanother pin may indicate an extension of 2 mm. The chuck can be adjustedwithin the X-, Y-, and Z-planes so that each indicia reflects the sameextension. In other words, the angle of the block can be adjusted sothat every pin indicates a 1 mm extension. When the indicia shows eachpin extending 1 mm, the surface of the block is aligned with the cuttingplane of the knife.

Although it is contemplated that a front pin can be the same componentas or directly coupled to a rear pin, it may be desirable to utilize atleast one class III lever between the front pin and the rear pin inorder to amplify the front pin's movement, such that the movement of therear pin is on a greater scale. In other words, when the front pin movesonly a few microns, it may be desirable to reflect this movement as alarger movement on the rear pins for the user's benefit. The resultingmagnification of the front pins movement can allow a user to adjust thefront pins and view slight movements on a small scale that would bedifficult for even a trained technician using conventional methods. Byusing additional class III levers, as discussed below, the user canobserve even greater magnification of the front pin's movement.

Referring to FIG. 3, in an example of how a front pin interacts with arear pin, a cross-sectional view of a pin alignment component 320 isshown. A front pin 350 extends from the front side of pin alignmentcomponent 320 and a rear pin 360 extends from the rear side of pinalignment component 320. Pin 350 contacts with a block specimen, whichforces the pin 350 against a lever 330. Lever 330 is designed as a classIII lever, discussed in further detail below. Lever 330 then appliespressure to pin 360, causing pin 360 to extend from pin alignmentcomponent 320. As described above, pin 360 can have indicia 340 toindicate the extension of the pin 360 from the pin alignment component320. The indicia 340 may be located on pin 360 between the lever 330 andthe edge of the pin alignment component 330. Pin alignment component 320can be hollowed to provide for movement of lever 330. Lever 330 can beconstructed of any durable material and can resist oxidation, such asstainless steel. It is desirable to use a material that can withstand alot of movement, is highly durable, and does not bend. It may also bedesirable to have a material that can withstand high temperature andpressure, such as in an autoclave.

Pins 350, 360 may be slidably engaged to lever 330. Upon a movement oflever 330, which is a slight rotational movement about a fulcrum, aslidable engagement can allow pins 350, 360 to slide in a horizontaldirection without substantial vertical forces. Additionally, theslidable engagement can allow pin 360 and lever 330 to return to astarting position when the block is no longer exerting pressure on pin350.

Referring to FIGS. 4 a to 4 c, a perspective view of a pin alignmentcomponent 400 is shown. Pin alignment component 400 has a plurality offront pins 450 arranged on the front surface and a plurality of rearpins 460 arranged on the rear surface of the pin alignment component400. This configuration of the pins 450, 460 is merely exemplary and isnot intended to be the only configuration or arrangement of pins on apin alignment component. Additionally, pin alignment component 400 isdepicted with a plurality of pins, but pin alignment component 400 canhave any number of pins. Employing the exemplary lever depicted in FIG.3, pin 450 extending from the front side of pin alignment component 400would have corresponding pin 460 extending from the rear at a differentposition along the surface of the pin alignment component 400. It isunderstood that the distance between these pins is dependent upon thelength of a lever (not shown in FIG. 4) that can connect the front andrear pins. In this exemplary embodiment, by positioning the pins 450 ina perpendicular manner on the front of pin alignment component 400, therear of pin alignment component 400 accordingly has pins 460 positionedalong the edge. It can be desirable to have a pin configuration,including the number of pins, that can reflect a block angle ondifferent axes such that a microtome user can accurately and preciselydetermine and adjust the alignment of the block specimen. Pin alignmentcomponent 400 can also have a level 430 to adjust the positioning of thepin alignment component 400 on a microtome. Level 430 can assist inorienting the pin alignment component with the clearance angle of theknife on the microtome.

In an alternative embodiment, referring to FIG. 5 a and across-sectional view through line A-A in FIG. 5 b, a pin alignmentcomponent 500 can have a plurality of pins 510 extending from a frontsurface of the pin alignment component to a rear surface of a contactsurface component 520. In this embodiment, a front surface of thecontact surface component 520 substantially abuts a sample in themicrotome. In this exemplary configuration, pins 510 engage the contactsurface component 520 with a ball-and-socket, but the pins 510 can haveany shape, such as a rectangular shape, that engages the contact surfacecomponent 520. Pins 510 can be constructed of any durable material andcan resist oxidation, such as stainless steel or plastic. It isdesirable to use a material that can withstand a lot of movement andfriction, and is highly durable. It may also be desirable to have amaterial that can withstand high temperature and high pressure, such asin an autoclave.

In order to effectuate a magnified view of the positioning between pins510, a lever system can be used such that pins 530 extending from a rearof pin alignment component 500 reflect a greater movement thanexperienced by pins 510. In other words, because pins 510 may have sucha small movement in response to a block specimen, as described above, itmay be desirable to magnify these movements on pins 530 so an operatorcan more easily observe these movements. Pins 510 engage a first lever540 that engages a connecting piece 550 that engages a second lever 560.Second lever 560 actuates pin 530. A barrier 570 is positioned betweenthe first lever 540 and the second lever 560. A spring 580 can bepositioned between barrier 570 and lever 560 to allow the lever 560 toreset to a starting position when a force on pin 510 is removed.

Lever 540 has a fulcrum 545, which is positioned approximately 0.5 mmfrom the contact point of pin 510 to contact surface component 520.Connecting piece 550 is approximately 10 mm from fulcrum 545 on a firstend and approximately 0.5 mm from a fulcrum 565 on lever 560. Connectingpiece 550 can pass through an aperture on barrier 570 to allow theconnecting piece 550 to slide as pressure is applied to lever 540 aswell as to keep connecting piece 550 in a proper position. Pin 530 ispositioned approximately 10 mm from fulcrum 565. It is understood thatthese measurements are merely exemplary and can be configured in avariety of dimensions. In one embodiment, a notch in a component isprovided to receive an end of another component for enabling the slidingof the components. For example, lever 540 can have a notch to receivepin 510.

As a result of this exemplary configuration, as contact surfacecomponent 520 contacts and substantially abuts a block specimen, thesurface of contact surface component 520 will adjust within the X-, Y-,and Z-planes to reflect the positioning of the block specimen.Accordingly, each pin 510 will also move to reflect the movement ofcontact surface component 520. Pin 530 reflects any movement of pin 510.The movement of pin 530, however, is a scaled magnification of themovement of pin 510. Because of the exemplary multiple class III leverconfiguration, a slight movement by pin 510, even if just a few microns,can be magnified by the movement of each lever. As a result, pin 530 canmagnify these slight movements so that the user can observe them withthe naked eye. For example, when pin 510 moves 10 μm, pin 530 moves 1mm. And once the movements are observed on pin 530, the user can adjustand calibrate the positioning of the chuck such that the pins 530 are insubstantial alignment with each other, thereby positioning the block ina plane that is in an ideal position relative to the knife. In oneexample, when one pin 530 extends 1 mm and another pin 530 extends 2 mm,the user can adjust the angles of the chuck so that the block abuttingcontact surface component 520 causes each pin 530 to extend the samedistance, e.g., 1 mm.

When working with ribonucleic acid (RNA), it is desirable to maintain anenvironment free of ribonuclease (RNase), a nuclease that catalyzes thehydrolysis of RNA. RNases are very common and can be present on handsand/or as airborne dust particles. As a result, when working with asample, such as a tissue containing RNA, it may be desirable to preparethe sample in an RNase-free environment. In order to achieve this typeof sterility, it may require an RNase-free sample and an RNase-freemicrotome.

In an alternative embodiment, a film or a wrapping, preferablydisposable, can be situated over a front surface of a contact surfacecomponent. In one exemplary method, the disposable film can be removablyattached to the contact surface component by electrostatic forces. Byusing the film on the contact surface component, the film can act as abarrier between the contact surface component and a block specimen forprotection or sterility purposes, such as in an RNase-free environment.

In order to amplify the slight movement of a pin, at least one class IIIlever can be used, as described herein. Any number of levers can be usedbetween a front pin and a rear pin, whereby adding additional leversincreases the amplification of effects on the front pin. Referring toFIGS. 6 a and 6 b, an exemplary operation of a lever configurationhaving two class III levers is shown. FIG. 6 a shows a pin 650 withoutany force exerted upon it by a pin alignment component (not shown). InFIG. 6 b, using arrows to show the general direction of movement of eachcomponent once a force is exerted, pin 650 causes a lever 640 (having afulcrum 620) to move, which causes a connecting piece 610 to move, whichcauses a lever 630 (having a fulcrum 670) to move, which causes a pin660 to move. As a result of this lever configuration, pin 660 can move agreater and more appreciable distance than pin 650. For example, if pin650 moves a slight distance, even on the scale of microns or nanometers(e.g., 10 μm), the lever configuration can amplify the resultingmovement of pin 660 to millimeters (e.g., 1 mm), which may be moreappreciable by a human technician.

Referring to FIGS. 7 a to 7 c, an exemplary method for determining alever configuration is shown. In this exemplary lever configuration,there are three components: a fulcrum, an effort, and a resistance. Inthe exemplary embodiment shown in FIG. 5 b, an exemplary fulcrum isfulcrum 545, an exemplary effort is pin 510, and an exemplary resistanceis connecting piece 550. In this exemplary embodiment, the fulcrum isthe same as a pivot point, the point where the resistance isstationarily fixed and allows the resistance to move about that point.Pressure is applied to the effort, which contacts the resistance nearthe fulcrum.

An exemplary method is provided to calculate the point at which theeffort should contact the resistance as measured from the fulcrum. Inthis example, when the effort is moved 5 μm, the resistance, which is20000 μm from the fulcrum, is to be moved 2000 μm. Referring to FIG. 7a, an angle x is to be determined where the desired movement A is 2000and the distance between the resistance and the fulcrum B is 20000.Calculating Tan(x)=A/B, x is approximately 5.71059 degrees. Next, thedistance between the fulcrum and the effort b, is to be determined.Calculating Tan(x)=a/b, where x is 5.71059 and a is 5, the distance b isabout 50 μm. Thus, the effort should contact the resistance at about 50μm from the fulcrum.

In a configuration, for example, where 50 μm may be too close to locatethe effort in relation to the fulcrum, it may be desirable to positionthe effort at 0.5 mm or 500 μm from the fulcrum. Referring to FIG. 7 b,an exemplary method is shown for determining the distance E of aresistance D from a fulcrum to cause a 5 μm change in an effort thatresults in a 2000 mm change in the resistance. In order to find an angley, Tan(y)=d/e, where desired change d is 5 and desirable effort positione is 500. So angle y is 0.57294 degrees. Using angle y, length E iscalculated by Tan(y)=D/E, where D is 20000, so length E is approximately2,000,000 μm or 200 cm. As a result, this length may be too big to fitinto the device.

Because positioning the effort 0.5 mm from the fulcrum may require toomuch length for the resistance, two levers can be used. A fold increasep is to be calculated for each lever. So a 5 μm change in the effortcauses a 2000 μm change in the resistance, so 5p²=2000. The foldincrease p is squared because one lever acting on another lever causesan exponential change, not an additive change. As a result, p is 20.

Assuming the effort can be positioned 500 μm from the fulcrum, a firstlever with a 20 fold change in a 5 μm effort would cause a 100 μm changein the resistance. Calculating Tan(y)=d/e, where d is 5 and e is 500,the angle y is 0.57294 degrees. However, because D is 100, thenTan(y)=D/E, where y is 0.57294, then E is approximately 10,000 μm or 1cm.

Referring to FIG. 7 c, the second lever would move 2000 μm, so length Dequals length g, because the resistance from the first lever has becomethe effort of the second lever. Calculating Tan(z)=g/h, where length gis 100 and length h is 500, z equals 11.30993 degrees. The length Hshould correspond to the length E of the first lever. CalculatingTan(z)=G/H, where z is 11.30993 and G is 2000, H is approximately 10,000μm or 1 cm, as calculated above with length E. In this example, there isa 20-fold increase from the first arm from 5 μm to 100 μm, and a 20-foldincrease from 100 μm to 2000 μm.

As described above, in an exemplary embodiment, referring to FIG. 7 d, apin alignment component 700 can have a plurality of levers 710 (usingefforts and resistances) to amplify the effort's movement, whichtranslates into a larger movement of the resistance. In this embodiment,a series of class III levers 710 are shown from a view of a front faceof the pin alignment component 700 for only a single pin. It isunderstood that pin alignment component 700 has sufficient depth toaccommodate these levers for each pin. It is also understood that eachpin can have any number of levers. Additionally, the spiralconfiguration shown is intended to be merely exemplary. A configurationhaving a plurality of levers can also be configured to use less spacewithin the pin alignment component, such as the exemplary embodimenthaving two class III levers shown in FIGS. 6 a and 6 b. This exemplaryembodiment may be desirable for more precise alignment of a microtomeknife with a sample. Also, in this exemplary embodiment, a digitaldisplay of pin movement may be used, as described below with respect toFIG. 9.

In yet another alternative embodiment, referring to FIG. 8, an alignmentdevice 800 is shown. Alignment device 800 has a knife holder component810 connected to an alignment component 820. A plurality of bristles 830are positioned on a front surface of the alignment component 820 tosubstantially contact a block specimen. Bristles 830 can be arranged ina rectangle, a cross, at least one horizontal line, at least onevertical line, or any other configuration. In one exemplary embodiment,an outer perimeter of the bristles is approximately the size of asample. By observing the deflection of the bristles 830, an operator candetermine how the bristles 830 are contacting the block specimen. Inother words, if a block specimen causes a region of bristles 830 todeflect more, the corresponding region of the block specimen is angledcloser to the alignment component 820. In that instance, the blockspecimen is not in alignment with the cutting plane of the knife. Theblock specimen can be considered aligned once all bristles 830 thatcontact the block specimen incur the same amount of deflection. In oneexemplary embodiment, the bristles 830 can be disposable.

In another embodiment, referring to FIG. 9, an alignment device 900 isshown having a knife holder component 910 connected to a pin alignmentcomponent 920. In this exemplary embodiment, pin alignment component 920has a plurality of pins 950 extending from a front side of the pinalignment component 920, as described in the exemplary embodiment inFIG. 2. However, it is understood that the embodiment described in FIG.9 is not limited to the embodiment described in FIG. 2. Pin alignmentcomponent 920 has a digital display 960, such as a liquid crystaldisplay, on a rear surface of pin alignment component 920. The digitaldisplay 960 can provide any number of numerical or visual indications,including a numerical representation of an extension of at least one ofthe pins 950. Alternatively, the digital display 960 can be positionedother than on the pin alignment component 920. In one exemplaryembodiment, the pins 950 are pressure sensitive.

The alignment devices described in any of the above exemplaryembodiments can be integrated into the microtome or can be an addedcomponent. In either configuration, any or all components of thealignment device can be disposable. However, the disposable nature of acomponent is not intended to be limited to a single use or any otherparticular number of uses.

The embodiments described above are intended to be exemplary. Oneskilled in the art recognizes that numerous alternative components andembodiments that may be substituted for the particular examplesdescribed herein and still fall within the scope of the invention.

1. A device for aligning a block specimen in a microtome, the devicecomprising: a knife holder component removably attached to a knifeholder of the microtome; a pin alignment component extending verticallyfrom the knife holder component in a direction substantially parallel tothe block specimen, the pin alignment component comprising: a pluralityof front pins extending from a front surface of the pin alignmentcomponent configured to slide in response to an angle of the blockspecimen; and a plurality of rear pins extending from a rear surface ofthe pin alignment component and coupled to the front pins; and an angleindicator indicating an angle between the knife holder component and thepin alignment component; wherein the rear pins are configured toindicate the extension of the front pins from the pin alignmentcomponent.
 2. The device according to claim 1, wherein the rear pinshave indicia of at least two colors.
 3. The device according to claim 1,wherein the rear pins have alphabetic or numeric indicia.
 4. The deviceaccording to claim 1, wherein the front pins are arranged along ahorizontal axis and a vertical axis of the front surface of the pinalignment component.
 5. The device according to claim 1, wherein therear pins are arranged substantially along the perimeter of the rearsurface of the pin alignment component.
 6. The device according to claim1, further comprising a contact surface component that engages the frontpins, wherein the contact surface component is configured to contact theblock specimen.
 7. The device according to claim 6, further comprising afilm extending across a front surface of the contact surface component.8. The device according to claim 7, wherein the film removably attachesusing electrostatic forces.
 9. A device for aligning a block specimen ina microtome, the device comprising: a knife holder component removablyattached to a knife holder of the microtome; a pin alignment componentextending vertically from the knife holder component in a directionsubstantially parallel to the block specimen, the pin alignmentcomponent comprising: a plurality of front pins extending from a frontsurface of the pin alignment component configured to slide in responseto an angle of the block specimen; and a plurality of rear pinsextending from a rear surface of the pin alignment component and coupledto the front pins; and at least one lever for coupling a front pin witha rear pin; wherein the rear pins are configured to indicate theextension of the front pins from the pin alignment component.
 10. Thedevice according to claim 9, further comprising a spring configured toallow the at least one lever to reset to a starting position.
 11. Thedevice according to claim 9, wherein the at least one lever comprises: afirst lever configured to move when a force is applied to a front pin: asecond lever configured to move when the first lever moves; and a thirdlever configured to move when the second lever moves and configured tomove a rear pin.